<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        .nav{
            width: 1000px;
            margin-left: auto;
            margin-right: auto;
            background: pink;
        }
        ul{
            list-style: none;
            line-height: 50px;
        }
        .drop-menu a{
            display: block;
        }
        a{
            text-decoration: none;
            color: #fff;
        }
        li{
            width: 100px;
            text-align: center;
            float: left;
        }
        .drop-down{
            position: relative;
        }
        .drop-menu{
            position: absolute;
            background: deeppink;
            display: none;
            width: 100px;
        }
        .row::after{
            content:"";
            display: table;
            clear: both;
        }
        .drop-down:hover .drop-menu{
            display: block;
        }
    </style>
</head>
<body>
    <ul class="nav row">
        <li class="drop-down">
            <a href="#">收藏夹</a>
            <div class="drop-menu">
                <a href="#">收藏宝贝</a>
                <a href="#">收藏店铺</a>
            </div>
        </li>
        <li><a href="#">卖家中心</a></li>
        <li><a href="#">联系客服</a></li>
    </ul>
</body>
</html>